On Jul 7, 11:20 pm, Charlie Savage <[EMAIL PROTECTED]> wrote: > Dan Janowski wrote: > > I think this is a vestige of the old fact that there could be two ruby > > objects that referred to the same XML node. Since I removed that and now > > there is only a one-to-one relationship between the ruby peer and the > > XML node, if == is equivalent to equal? and equal? is object identity, > > then it makes sense to do as you say. Should eql? take on the code of > > the current ==? > > Good point, the new memory model definitely changes things. Currently, > the == operator in libxml is an alias for eql?, so there is only one method. > > I did a bit of research to understand general ruby conventions. The > best write ups I found are: > > http://groups.google.com/group/comp.lang.ruby/browse_thread/thread/57...http://www.texperts.com/2007/10/16/navigating-the-equality-maze/ > > I like thinking about it this way (taken from one of the comments in the > first post): > > equal? object identity test > > eql? strict equality test, 1.eql?(1.0) is false > (defaults to identity) > > == loose equality test, 1 == 1.0 is true > (defaults to identity) > > Usually == is the same as eql?, but not always (see the numeric classes > for example). > > In theory, you are supposed to override eql? for your own classes and > perhaps ==. If you do override eql? you are also supposed to override hash. > > FOr libxml, I don't see how a custom eql? methods provides any benefits > - why would you compare two xml nodes for equality, and if you did, what > does that mean? If the text content is the same, but the document is > different, is that still equality? > > The big downside is performance, all of a sudden code like this: > > node1 == node2 > > becomes very slow. In addition, lookups for hash tables or keys that > contain nodes as keys also becomes slow. > > So, I don't think defining eql? to do a text comparison while defining > == to be object identity is a good idea because it would be inconsistent > with existing ruby conventions and code. So I propose we remove the > overriden eql? method, thereby causing the == operator to default to an > object identity test.
Hmmm... How does the C library itself handle comparison? T. _______________________________________________ libxml-devel mailing list libxml-devel@rubyforge.org http://rubyforge.org/mailman/listinfo/libxml-devel
